
<?php
if( !class_exists('Mysql') ){
    class Mysql {
        private $db_host; //数据库主机
        private $db_user; //数据库用户名
        private $db_pwd; //数据库用户名密码
        private $db_database; //数据库名
        private $conn; //数据库连接标识;
        private $result; //执行query命令的结果资源标识
        private $sql; //sql执行语句
        private $row; //返回的条目数
        private $coding; //数据库编码，GBK,UTF8,gb2312
        private $bulletin = true; //是否开启错误记录
        private $show_error = false; //测试阶段，显示所有错误,具有安全隐患,默认关闭
        private $is_error = false; //发现错误是否立即终止,默认true,建议不启用，因为当有问题时用户什么也看不到是很苦恼的
        private static $singleInstance = null;

        /*构造函数*/
        public function __construct($db_host, $db_user, $db_pwd, $db_database, $conn, $coding) {
            $this->db_host = $db_host;
            $this->db_user = $db_user;
            $this->db_pwd = $db_pwd;
            $this->db_database = $db_database;
            $this->conn = $conn;
            $this->coding = $coding;
            $this->connect();
        }

        /**
         * 获取数据库实例
         * @return Mysql
         */
        public static function getInstance(){
            if( self::$singleInstance === null || !( self::$singleInstance instanceof self ) ){
                include_once 'config.php';
                self::$singleInstance = new Mysql( DB_HOST , DB_USER , DB_PASS , DB_NAME , null , 'utf8mb4' );
            }
            return self::$singleInstance;
        }

        /*数据库连接*/
        public function connect() {
            if ($this->conn == "pconn") {
                //永久链接
                $this->conn = mysqli_connect('p:'.$this->db_host,$this->db_user,$this->db_pwd,$this->db_database) or die('Unale to connect');
            } else {
                //即时链接
                $this->conn = mysqli_connect($this->db_host,$this->db_user,$this->db_pwd,$this->db_database) or die('Unale to connect');
            }

            //检查连接是否成功
            if (mysqli_connect_errno()){
                //注意mysqli_connect_error()新特性
                die('Unable to connect database!'). mysqli_connect_error();
            }
            mysqli_query( $this->conn , "SET NAMES $this->coding" );
        }

        /*数据库执行语句，可执行查询添加修改删除等任何sql语句*/
        public function query($sql) {
            if ($sql == "") {
                $this->show_error("SQL语句错误：", "SQL查询语句为空");
            }
            $this->sql = $sql;

            $result = mysqli_query( $this->conn , $this->sql );

            if (!$result) {
                //调试中使用，sql语句出错时会自动打印出来
                if ($this->show_error) {
                    $this->show_error("错误SQL语句：", $this->sql);
                }
            } else {
                $this->result = $result;
            }
            return $this;
        }

        /*创建添加新的数据库*/
        public function create_database($database_name) {
            $database = $database_name;
            $sqlDatabase = 'create database ' . $database;
            $this->query($sqlDatabase);
        }

        /*查询服务器所有数据库*/
        //将系统数据库与用户数据库分开，更直观的显示？
        public function show_databases() {
            $this->query("show databases");
            echo "现有数据库：" . $amount = $this->db_num_rows();
            echo "<br />";
            $i = 1;
            while ($row = $this->fetch_array( $this->result )) {
                echo "$i $row[Database]";
                echo "<br />";
                $i++;
            }
        }

        //以数组形式返回主机中所有数据库名
        public function databases() {
            $rs = mysqli_query( $this->conn , 'show databases' );
            return $rs;
        }

        /*查询数据库下所有的表*/
        public function show_tables($database_name) {
            $this->query("show tables");
            echo "现有数据库：" . $amount = $this->db_num_rows();
            echo "<br />";
            $i = 1;
            while ($row = $this->fetch_array($this->result)) {
                $columnName = "Tables_in_" . $database_name;
                echo "$i $row[$columnName]";
                echo "<br />";
                $i++;
            }
        }

        /*
        mysql_fetch_row()    array  $row[0],$row[1],$row[2]
        mysql_fetch_array()  array  $row[0] 或 $row[id]
        mysql_fetch_assoc()  array  用$row->content 字段大小写敏感
        mysql_fetch_object() object 用$row[id],$row[content] 字段大小写敏感
        */

        /*取得记录集,获取数组-索引和关联,使用$row['content'] */
        public function fetch_array() {
            $data = array();
			if( $this->result ){
					while($row = mysqli_fetch_assoc($this->result)){
					$data[] = $row;
				}
			}
            return $data;
        }

        //获取关联数组,使用$row['字段名']
        public function fetch_assoc() {
            return mysqli_fetch_assoc($this->result);
        }

        //获取数字索引数组,使用$row[0],$row[1],$row[2]
        public function fetch_row() {
            return mysqli_fetch_row($this->result);
        }

        //获取对象数组,使用$row->content
        public function fetch_Object() {
            return mysqli_fetch_object($this->result);
        }

        //简化查询select
        public function findall($table) {
            $this->query("SELECT * FROM $table");
        }

        //简化查询select
        public function select($table, $columnName = "*", $condition = '', $debug = '') {
            $condition = $condition ? ' Where ' . $condition : NULL;
            if ($debug) {
                echo "SELECT $columnName FROM $table $condition";
            } else {
                $this->query("SELECT $columnName FROM $table $condition");
            }
        }

        //简化删除del
        public function delete($table, $condition, $url = '') {
            if ($this->query("DELETE FROM $table WHERE $condition")) {
                return true;
            }
        }

        //简化插入insert
        public function insert($table, $columnName, $value, $url = '') {
            if ($this->query("INSERT INTO $table ($columnName) VALUES ($value)")) {
                return true;
            }
        }

        //简化修改update
        public function update($table, $mod_content, $condition, $url = '') {
            //echo "UPDATE $table SET $mod_content WHERE $condition"; exit();
            if ($this->query("UPDATE $table SET $mod_content WHERE $condition")) {
                return true;
            }
        }

        /*取得上一步 INSERT 操作产生的 ID*/
        public function insert_id() {
            return mysqli_insert_id( $this->conn );
        }

        //指向确定的一条数据记录
        public function db_data_seek($id) {
            if ($id > 0) {
                $id = $id -1;
            }
            if (!@ mysqli_data_seek($this->result, $id)) {
                $this->show_error("SQL语句有误：", "指定的数据为空");
            }
            return $this->result;
        }

        // 根据select查询结果计算结果集条数
        public function db_num_rows() {
            if ($this->result == null) {
                if ($this->show_error) {
                    $this->show_error("SQL语句错误", "暂时为空，没有任何内容！");
                }
            } else {
                return mysqli_num_rows($this->result);
            }
        }

        // 根据insert,update,delete执行结果取得影响行数
        public function db_affected_rows() {
            return mysqli_affected_rows( $this->conn );
        }

        //输出显示sql语句
        public function show_error($message = "", $sql = "") {
            if (!$sql) {
                echo "<font color='red'>" . $message . "</font>";
                echo "<br />";
            } else {
                echo "<fieldset>";
                echo "<legend>错误信息提示:</legend><br />";
                echo "<div style='font-size:14px; clear:both; font-family:Verdana, Arial, Helvetica, sans-serif;'>";
                echo "<div style='height:20px; background:#000000; border:1px #000000 solid'>";
                echo "<font color='white'>错误号：12142</font>";
                echo "</div><br />";
                echo "错误原因：" . mysql_error() . "<br /><br />";
                echo "<div style='height:20px; background:#FF0000; border:1px #FF0000 solid'>";
                echo "<font color='white'>" . $message . "</font>";
                echo "</div>";
                echo "<font color='red'><pre>" . $sql . "</pre></font>";
                $ip = $this->getip();
                if ($this->bulletin) {
                    $time = date("Y-m-d H:i:s");
                    $message = $message . "\r\n$this->sql" . "\r\n客户IP:$ip" . "\r\n时间 :$time" . "\r\n\r\n";

                    $server_date = date("Y-m-d");
                    $filename = $server_date . ".txt";
                    $file_path = "error/" . $filename;
                    $error_content = $message;
                    //$error_content="错误的数据库，不可以链接";
                    $file = "error"; //设置文件保存目录

                    //建立文件夹
                    if (!file_exists($file)) {
                        if (!mkdir($file, 0777)) {
                            //默认的 mode 是 0777，意味着最大可能的访问权
                            die("upload files directory does not exist and creation failed");
                        }
                    }

                    //建立txt日期文件
                    if (!file_exists($file_path)) {

                        //echo "建立日期文件";
                        fopen($file_path, "w+");

                        //首先要确定文件存在并且可写
                        if (is_writable($file_path)) {
                            //使用添加模式打开$filename，文件指针将会在文件的开头
                            if (!$handle = fopen($file_path, 'a')) {
                                echo "不能打开文件 $filename";
                                exit;
                            }

                            //将$somecontent写入到我们打开的文件中。
                            if (!fwrite($handle, $error_content)) {
                                echo "不能写入到文件 $filename";
                                exit;
                            }

                            //echo "文件 $filename 写入成功";

                            echo "——错误记录被保存!";

                            //关闭文件
                            fclose($handle);
                        } else {
                            echo "文件 $filename 不可写";
                        }

                    } else {
                        //首先要确定文件存在并且可写
                        if (is_writable($file_path)) {
                            //使用添加模式打开$filename，文件指针将会在文件的开头
                            if (!$handle = fopen($file_path, 'a')) {
                                echo "不能打开文件 $filename";
                                exit;
                            }

                            //将$somecontent写入到我们打开的文件中。
                            if (!fwrite($handle, $error_content)) {
                                echo "不能写入到文件 $filename";
                                exit;
                            }

                            //echo "文件 $filename 写入成功";
                            echo "——错误记录被保存!";

                            //关闭文件
                            fclose($handle);
                        } else {
                            echo "文件 $filename 不可写";
                        }
                    }

                }
                echo "<br />";
                if ($this->is_error) {
                    exit;
                }
            }
            echo "</div>";
            echo "</fieldset>";

            echo "<br />";
        }

        //释放结果集
        public function free() {
            @ mysqli_free_result($this->result);
        }

        //数据库选择
        public function select_db($db_database) {
            return mysqli_select_db($this->conn , $db_database);
        }

        //查询字段数量
        public function num_fields($table_name) {
            //return mysql_num_fields($this->result);
            $this->query("select * from $table_name");
            echo "<br />";
            echo "字段数：" . $total = mysql_num_fields($this->result);
            echo "<pre>";
            mysqli_fetch_field($this->result);
            echo "</pre>";
            echo "<br />";
        }

        //取得 MySQL 服务器信息
        public function mysql_server($num = '') {
            switch ($num) {
                case 1 :
                    return mysqli_get_server_info( $this->conn ); //MySQL 服务器信息
                    break;

                case 2 :
                    return mysqli_get_host_info( $this->conn ); //取得 MySQL 主机信息
                    break;

                case 3 :
                    return mysqli_get_client_info(); //取得 MySQL 客户端信息
                    break;

                case 4 :
                    return mysqli_get_proto_info( $this->conn ); //取得 MySQL 协议信息
                    break;

                default :
                    return mysqli_get_client_info(); //默认取得mysql版本信息
            }
        }

        //析构函数，自动关闭数据库,垃圾回收机制
        public function __destruct() {
            if (!empty ($this->result)) {
                $this->free();
            }
            mysqli_close($this->conn);
        } //function __destruct();

        /*获得客户端真实的IP地址*/
        function getip() {
            if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown")) {
                $ip = getenv("HTTP_CLIENT_IP");
            } else
                if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown")) {
                    $ip = getenv("HTTP_X_FORWARDED_FOR");
                } else
                    if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown")) {
                        $ip = getenv("REMOTE_ADDR");
                    } else
                        if (isset ($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown")) {
                            $ip = $_SERVER['REMOTE_ADDR'];
                        } else {
                            $ip = "unknown";
                        }
            return ($ip);
        }
        function inject_check($sql_str) { //防止注入
            $check = eregi('select|insert|update|delete|\'|\/\*|\*|\.\.\/|\.\/|union|into|load_file|outfile', $sql_str);
            if ($check) {
                echo "输入非法注入内容！";
                exit ();
            } else {
                return $sql_str;
            }
        }
        function checkurl() { //检查来路
            if (preg_replace("/https?:\/\/([^\:\/]+).*/i", "\\1", $_SERVER['HTTP_REFERER']) !== preg_replace("/([^\:]+).*/", "\\1", $_SERVER['HTTP_HOST'])) {
                header("Location: http://www.dareng.com");
                exit();
            }
        }

    }
}
?>
